Genetic Counseling for BRCA Mutation Testing

Risk Assessment and Genetic Counseling

Genes are the individual packets of information we inherent from our parents. They help determine traits like hair color, eye color, and susceptibility to disease. All our genes are present in pairs. One gene in each pair is passed down from our mother and the other from our father. Genes provided instructions that tell a cell what to do. Some genes instruct a cell to grow and divide. Other genes are responsible for telling cells how to break down certain substances in the body that are harmful.

Genes and environmental factors together play a role in the occurrence of cancer. There are different causes for cancer in one individual versus another. Sometimes, we see a specific pattern of cancer in the family called a cancer syndrome. A “syndrome” describes a group of features that repeatedly occur together. A cancer syndrome is present when several family members have the same type of cancer, or a cluster of specific forms of cancer. A single susceptibility gene in a family causes these cancers. Other forms of cancer may be caused by a variety of other mechanisms, such as familial exposure to environmental or dietary risk factors, several genes working together to contribute to cancer formation, or even by chance alone.

Your family history is suggestive of an inherited susceptibility to breast and ovarian cancer.

BRCA1 and BRCA2 are genes inherited in an autosomal dominant pattern. Everyone has these genes – one from their mother and one from their father. Certain families have inherited altered or mutated versions of these genes that increase their risk for cancer. When an individual carries an autosomal dominant gene mutation, there is a 50% or 1 in 2 chance that each child could inherit that altered gene. These genes can be inherited from either the mother or the father’s side of the family. It is best, but not always possible to begin genetic testing on a family member who has had cancer so that the test is easier to interpret.

Not everyone with a mutation will develop cancer. Women who carry an altered BRCA1 or BRCA2 gene have an estimated 60% lifetime risk of developing breast cancer. Women in the general population have a 1 in 8 or 12% risk to develop breast cancer in their lifetime. Only about 10% of women with breast cancer will have a BRCA mutation.

Women who carry an altered BRCA1 gene have an estimated 40% lifetime risk of developing ovarian cancer and women who have an altered BRCA2 mutation have an estimated 10-20% lifetime risk of developing ovarian cancer. The general population risk of ovarian cancer is 1 in 70 or 1.4% by age 90.

Testing positive for a BRCA mutation allows us to aggressively screen for breast and ovarian cancer. Screening guidelines change if you carry a mutation. Also, there are effective prevention strategies that can be initiated. Prophylactic surgery with mastectomy and/or oopherectomy is also an option considered by many women.

I have read and understand that BRCA mutation analysis is available and that my family history makes me a candidate for testing.